This invention realtes generally to garments made of non-woven textiles, and in particular to a standardized expandable cap made of such textiles for protecting the head of newborn babies, the cap adjusing itself to the head of the wearer regardless of head size.
Body temperature which is nominally at 98.6.degree. F. is determined by the relationship existing between the amount of heat generated internally, which depends on basal metabolism, and the amount escaping from the body. Additional heat is produced as a result of muscular activity. Body heat is dissipated by an increase in radiation, conduction or evaporation from the skin surface.
Thus the skin is the interface between the internallyheated body and the atmosphere and is in heat exchange relationship therewith. If the heat produced by a body surpasses heat losses therefrom, this gives rise to fever or hyperthermia; but if heat losses exceed production, then the body temperature falls below the nominal value, giving rise to shivering and hypothermia.
The nerve centers for regulating body temperature are located in the forebrain region or hypothalamus. These centers sense changes in blood temperature and act to stimulate an appropriate activity to maintain the desired temperature level. Thus, should there be a drop in temperature, there will be a greater expenditure of energy to contribute heat to the blood; and should there be a rise in temperature, sweating and other actions will take place to increase heat losses.
When in a cold climate an adult dresses to keep warm; but should he fail to wear a hat, he may remain cold even if clothed in wool garments; for much more body heat is dissipated from the head than from other areas of the body. And should the adult be more or less bald, the heat losses are then still greater.
A typical newborn babe has a virtually hairless skull, and in the hours immediately following birth, his ability to regulate body temperature is not yet fully operative. It becomes important, therefore, in these critical hours to reduce heat losses from the head of the infant.
Hence in the maternity wards of many hospitals, it is the mandated practice to have all newborn babies wear a cap for the first five or six hours of life to reduce the otherwise considerable loss of heat from the head. And because disposable caps suitable for newborn babies are not commercially available, hospitals presently make their own caps, usually out of a ribbed fabric, for such knitted fabrics have some degree of stretch, and a cap of standard size will fit over the head of the infant regardless of his or her head size.
Apart from the time and expense involved in making such ribbed fabric caps, is the problem of satisfying basic medical requirements. The cap must, of course, be non-toxic and non-allergenic, and it must also be sterile. These requirements are difficult to meet in a hospital-manufactured cap, particularly if the cap must be laundered after use and sterilized. Moreover, the use of a ribbed fabric may afford excessive thermal insulation and result in an overly warm infant. Thus while it is vital that heat loss from the infant's head be reduced, some degree of cooling is also desirable. Accordingly, the ideal newborn cap is one which stabilizes body heat loss, not one which raises body temperature.
It is known to fabricate garments of non-woven synthetic plastic fibers and to use ultrasonic welding techniques for seaming such garments. Thus in my prior U.S. Pat. No. 4,327,448, a non-woven fabric sheet is formed into disposable shorts by cutting the sheet into blanks, a pair of such blanks being ultrasonically welded together to define an open-ended tube which is then further processed to create shorts. But the technique disclosed in my prior patent does not lend itself to making caps for newborn babies which satisfy the special requirements imposed on such caps. Thus many non-woven materials have a texture irritating to the sensitive skin of an infant, or they include binders and other chemical agents to which an infant may be allergic.